WASHINGTON -- The top U.S. intelligence official says assessments of Russian meddling in the 2016 election have been "clear" and describes the Kremlin's efforts to undermine the United States' democracy as "ongoing" and "pervasive."

The statement from Dan Coats, the Director of National Intelligence, followed comments earlier Monday from President Donald Trump at a news conference with Russian leader Vladimir Putin in Helsinki where Trump cast doubt on the credibility of U.S. intelligence assessments.

Trump said he had "great confidence" in U.S. intelligence but that Putin's denial of election meddling was "extremely strong and powerful."

Trump has long been at odds with his own intelligence community, largely clashing over a report released by U.S. intelligence officials concluding that Putin ordered "an influence campaign" in 2016 aimed at helping Trump win the presidency.